Kidney transplantation
Mark Davenport, James D. Geiger, Nigel J. Hall, Steven S. Rothenberg in Operative Pediatric Surgery, 2020
Once the arterial reconstruction is completed, venous outflow is established. The renal artery is then gently occluded with vascular pickups, while restoring distal arterial flow. After several cardiac cycles, inflow to the kidney is established. The kidney should be carefully inspected. Optimally, a uniform pink color and normal turgor are followed promptly by the production of urine. Engorgement of the kidney suggests venous obstruction. This may be due to an imperfect anastomosis, but it is more commonly attributable to compression of the vena cava by one of the retractor blades. A thrill in the renal artery should be developed over time. It is helpful to evaluate flow in the renal parenchyma with a hand-held Doppler probe, paying special attention to evaluating flow in diastole. Heparin need not be reversed with protamine sulfate unless troublesome bleeding occurs. Following establishment of hemostasis and assuming satisfactory appearance of the kidney, attention is then turned to the urinary reconstruction.
Anticoagulation
Harold R. Schumacher, William A. Rock, Sanford A. Stass in Handbook of Hematologic Pathology, 2019
Unfractionated heparin can be administered subcutaneously (SC) or intravenously (IV). Usually an IV loading dose of 5000–10,000 units is followed by continuous IV administration (see Tables 5 and 6). Subcutaneous administration of UFH has been used effectively for prophylactic heparinization in high-risk settings, such as abdominal or orthopedic surgery. Heparin’s anticoagulant effect is monitored clinically using the aPTT. A “therapeutic range” is usually 1.5–1.7 times (×) the median of the respective laboratory’s normal aPTT range. Using the patient’s initial aPTT is preferable to using the laboratory’s “normal” control values. A typical protocol for heparin treatment and monitoring after venous thromboembolism (VTE) is shown in Table 5. The treatment of VTE with heparin is dependent on many clinical variables. Heparin dosage is titrated appropriately using the aPTT, and a sample protocol is shown in Table 6(16). Attaining a therapeutic level of anticoagulation within the first 24 hr after a presumptive diagnosis of TE may markedly limit the subsequent propagation of the thrombus and embolism (17). The proposed dose for enoxaprin for treatment of an acute deep venous thrombosis (DVT) is 1 mg/kg subcutaneous every 12 hr (17,18).
Safe and strategic vascular access
Peter A. Schneider in Endovascular Skills: Guidewire and Catheter Skills for Endovascular Surgery, 2019
The patient’s arm is abducted and placed on an armboard (Figure 2.15). A circumferential preparation of the arm is performed. The brachial artery pulse is palpated just proximal to the antecubital crease where the biceps has generally thinned to its tendinous portion. Ultrasound guidance is strongly recommended. If not available, the artery can be trapped between the forefinger and the third finger of the nondominant hand. The tips of the two fingers are held at enough distance to allow the artery to pass underneath without compressing it significantly. The 21-gauge micropuncture needle is advanced at a 45-degree angle by the dominant hand. The goal is for the needle tip to enter the anterior wall of the artery in the space between the two fingers. When backbleeding occurs, a short 0.018-inch diameter guidewire is passed. Backbleeding through the micropuncture needle is usually not pulsatile because of its small caliber. The needle must be moved and manipulated slowly and any backbleeding carefully assessed. Heparin is administered to prevent thrombosis. Intra-arterial nitroglycerine or papaverine may be required if spasm of the upper extremity arteries occurs. Ultrasound can be used to visualize the guidewire advancing into the axillary artery. If the brachial artery is really small (less than 3–4 mm), consider moving to the contralateral side. Such patients may have a high origin of the radial artery.
SARS-CoV-2 Infection Dysregulates Host Iron (Fe)-Redox Homeostasis (Fe-R-H): Role of Fe-Redox Regulators, Ferroptosis Inhibitors, Anticoagulants, and Iron-Chelators in COVID-19 Control
Published in Journal of Dietary Supplements, 2023
Sreus A.G. Naidu, Roger A. Clemens, A. Satyanarayan Naidu
Heparin as a therapeutic anticoagulant is linked to a 10 − 15% risk of significant bleeding (305). Factors that may increase bleeding risk include old age, recent trauma or surgery, cardiopulmonary resuscitation, longer hospital stay, and decreased white blood cell/platelet counts (306). These risk factors are common among patients with COVID-19. Heparin-induced thrombocytopenia (HIT), a rare complication of heparin therapy, is estimated to occur in 0.2–3% of patients (307). The adverse HIT reaction results from the development of antibodies against platelet factor 4, which triggers thrombocytopenia. Repurposing of heparin and its derivatives as first-line therapeutics against SARS-CoV-2 is promising; however, this clinical approach needs an in-depth evaluation (308).
A comparison of four methods to estimate dim light melatonin onset: a repeatability and agreement study
Published in Chronobiology International, 2023
Raphaëlle Glacet, Eve Reynaud, Ludivine Robin-Choteau, Nathalie Reix, Laurence Hugueny, Elisabeth Ruppert, Pierre A. Geoffroy, Ülker Kilic-Huck, Henri Comtet, Patrice Bourgin
Blood samples were collected during 3 days (40 samples of 8 mL). Samples used in this study were those collected during the evening/night periods (10 samples each), hourly from 5 h before lights off (hour at which participants went to bed and turned the lights off during the protocol) to 1 h after lights off, then every 2 h from 1 h after lights off to 7 h after lights off. Light exposure before lights off was dim light (<8 lux) and samples from lights off to 8 h after were collected when the subjects were asleep in total darkness. The subjects kept a peripheral venous catheter and were perfused with heparin sodium diluted in 0.9% NaCl during the whole protocol to avoid blood coagulation in the peripheral venous catheter. A platelet count was made to confirm the absence of a heparin-induced thrombocytopenia. Blood samples were collected in EDTA tubes, centrifuged immediately after and the plasma volume was distributed in microtubes. All samples were frozen immediately at −20 °C and then stored at −80 °C until melatonin assessments.
Treatment of severe COVID-19: an evolving paradigm
Published in Expert Opinion on Pharmacotherapy, 2022
The therapeutic approach for patient severe COVID-19 involves a combination of medications: the systemic corticosteroid dexamethasone improves mortality for the treatment of severe COVID-19, while the antiviral remdesivir may have modest but shows no statistically significant benefit in mortality or other clinical outcomes in patients with severe disease [21–23]. Prophylactic anticoagulation with heparin is now recommended to prevent blood clots because therapeutic anticoagulation did not improve survival [24,25]. Other immunomodulators, such as baricitinib and tocilizumab, are also recommended for some hospitalized patients (Table 1). This multifactorial approach has consistently shown benefit, but mortality from severe COVID-19 remains unacceptably high and better treatment options are urgently needed [14,26,27].
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